Just don't like the tendency (shown most especially in assumptions about the Bolians based on Mr. Mott's personality) to see one example of a species then assuming they are the statistical embodiment of their entire culture.
In the case of Mister Mott's species, we saw a young woman of that species who was a Starfleet cadet, she was grey and not blue, and seemed to be a fairly interesting person. Now, as it turned out she was a alien imposter, but it does show that not everyone of that species is a blue skinned barber.
And I personally don't think that these two twins were actually "cat people." Yes they had tails, there are fur-less cats, and the script referred to them as cats. I just don't feel that they were cats.